Measurement of therapeutic drug levels is usually only necessary
for drugs with a 'narrow therapeutic window': that is, where too
much of the drug may be toxic, and too little of the drug will be
ineffective

This test examines your breath for the
presence of Helicobacter pylori bacteria, which can cause
gastritis (inflammation of the mucous membrane of the stomach) or
ulcers in the stomach and small intestine.

This test examines your urine using a
molecular-amplification technique known as 'polymerase chain
reaction' (PCR). The PCR testing process can detect the presence of
bacterial and/or parasite DNA that might indicate that you have
chlamydia, gonorrhoea, or trichomoniasis.

Although urine in the bladder is normally sterile (containing no
organisms), bacteria are usually present around the opening of the
urethra (the tube that leads from the bladder to the outside of the
body). Urine collection for MCS must be performed carefully in
order to avoid contaminating the sample with these bacteria.

You have been requested to have a urine drug screen performed.
This test is only performed at certain collection centres. An
appointment is preferred. You will be given an appointment time at
a centre close to you.